You know that moment when you’re standing in front of your closet on a chilly morning, trying to figure out how not to freeze… and you end up throwing on three layers, only to be sweaty indoors but still cold outside? 😅 Been there.

Well, turns out that it's not about how many layers you wear.

It’s about what those layers are made of.

And once I figured this out, everything changed. Both in my everyday closet and when packing for trips.

Not to mention… fabrics matter if you don’t want to add a bunch of extra bulk. Because let’s be honest, who wants to feel like a walking marshmallow just to stay warm? 🙅🏻‍♀️

Why fabrics matter more than you think...

I grew up on the Caribbean coast of Venezuela, where the only “layers” I ever wore were cover-ups to the beach. I had no idea what a good sweater even was.

Fast forward to when I was 27, and I moved to Chicago, where I lived for 7 years... a city that will humble you real quick when it comes to winter dressing. If your sweater isn’t pulling its weight, you’ll find out real quick while waiting for the “L” in February 🥶.

💡That’s when I learned: it’s not about piling on more clothes. It’s about choosing the right fabrics.

One great cashmere crewneck will always beat three acrylic layers.

And even though I don’t usually travel to super cold places anymore (I’m still a warm-weather girl at heart 🌴), I want you to know this: you can absolutely travel light and stay warm, even if you’re heading to freezing Christmas markets in Europe.

The fabrics you pack are what make that possible. So let's learn about the warmest and least bulky fabrics to invest in this season!

But first, look at the cute little cheat-sheet I put together for you! Make sure to save it on Pinterest. (for you to have for future reference, but it also helps me a ton that you save it to any of your Pinterest boards 🙏🏼)

Best Fabrics Ranked: Least Bulky → Bulkiest

Okay, so here’s the thing—warmth is totally subjective (I’m always the cold one 🥶). But bulk? That’s a fact. So I ranked these fabrics from least bulky to bulkiest, with a quick personal score for warmth and carry-on friendliness so you know exactly what’s worth the suitcase space.

1️⃣ Cashmere – Lightweight, soft, luxe

🌡️ Warmth: 8/10

🧳 Carry-on friendliness: 10/10

Best for: Sweaters, scarves, wraps and even skirts and joggers.

Why it works: Packs down tiny but delivers major warmth. Looks chic with zero effort and layers easily under coats.

2️⃣ Alpaca – Ultra-cozy, hypoallergenic

🌡️ Warmth: 9/10

🧳 Carry-on friendliness: 9/10

​Best for: sweaters, ponchos, scarves, wraps.

Why it works: Alpaca fibers are hollow, which means they trap heat better than wool while staying lightweight. They’re also naturally soft and less prickly, so if regular wool makes you itchy, alpaca should feel better.

3️⃣ Wool (esp. Merino) – Classic, breathable, insulating

🌡️ Warmth: 9/10

🧳 Carry-on friendliness: 9/10

Best for: Base layers (merino tees/long sleeves), sweaters, coats, socks.

Why it works: Incredible warmth-to-weight ratio and odor resistant (perfect for rewearing on trips). Merino wool is the ultimate layering fabric!

4️⃣ Sustainable Fabrics (TENCEL™, organic cotton, recycled blends)

🌡️ Warmth: 6/10

🧳 Carry-on friendliness: 8/10

Best for: Long-sleeve tees, layering tops, dresses, travel basics.​

Why it works: These fabrics are soft, breathable, and planet-friendly, but they’re not the warmest on their own. That’s actually a good thing when you’re packing light — they make perfect under layers on cold days and can stand alone when the weather warms up.

Nothing’s worse than packing only heavy sweaters and then sweating through a sunny fall afternoon. These type of fabrics give you so much flexibility when on the road.

5️⃣ Cotton (Brushed, Thermal, Flannel)

🌡️ Warmth: 6/10

🧳 Carry-on friendliness: 8/10

Best for: Flannel shirts, thermal tops, casual button-downs.​

Why it works: Cozy and comfortable, but not enough for deep winter unless layered. A fall favorite—especially flannel shirts layered over cotton tees.

6️⃣ Fleece – Cozy, casual, quick-drying

🌡️ Warmth: 7/10

🧳 Carry-on friendliness: 6/10

Best for: Zip-ups, pullovers, casual jackets.

Why it works:Fleece is warm, soft, and dries really fast — perfect if you need to wash it mid-trip or get caught in the rain. It’s lightweight but can feel a bit bulky in a suitcase, so stick to one or two pieces (and wear them on travel days). Great for cozy airport outfits, layering under a jacket, or casual sightseeing days.

7️⃣ Polyester & Acrylic Blends – Affordable, shape-holding

🌡️ Warmth: 4/10

🧳 Carry-on friendliness: 6/10

Best for: Sweaters, rain jackets, coat linings.

Why it works: Fine in blends (with wool, cotton, or viscose), but avoid 100% versions—they pill, trap sweat, and don’t insulate well.

Good for budget-friendly sweaters and of course, rain jackets that keep you dry, but rarely warm.

8️⃣ Corduroy – Sturdy, textured, structured

🌡️ Warmth: 7/10

🧳 Carry-on friendliness: 6/10

​Best for: Pants and skirts.

Why it works: Cozy and stylish with that retro fall vibe, but heavier and harder to compress in a suitcase. One piece is plenty for a fall trip.

9️⃣ Denim – Durable, stylish, all-season

🌡️ Warmth: 5/10

🧳 Carry-on friendliness: 5/10

Best for: Jeans, jackets, skirts, button down shirts.

Why it works: A timeless wardrobe staple, but heavy and slow to dry. For packing light, limit yourself to one pair of jeans (or a denim jacket) max. Definitely skip if traveling in the middle of winter. It's useless if it's very cold.

✅ Quick takeaway:

For travel, focus on cashmere, merino wool, and alpaca (best warmth-to-weight ratio). Use cotton, sustainable fabrics, or fleece as layering bases. Keep corduroy and denim minimal since they hog suitcase space.

And remember this info is always right there for you: check the product tag if you’re shopping in person, or the product description if you’re shopping online.

Of course, there are plenty of other fabrics out there—like leather, sherpa, and velvet—but these nine are the ones you’ll run into the most (and the ones that matter most for everyday closets and packing light).

Master these, and you’ll already be way ahead of the game when it comes to staying warm and stylish.

My two cents...

If you’re tired of having a closet full of sweaters that look cute but don’t actually keep you warm, I’ve been there too. At one point, I had drawers packed with “cozy” pieces that never kept me warm.

Everything changed when I finally paid attention to fabrics. They really do make all the difference.

So if you’re someone who’s always cold, try something different this year: invest in pieces that work. One sweater at a time, you don't need a full makeover in one season. Little by little.

If you stop buying random sweaters without reading the description tag, I promise you will see a HUGE difference over time.

Hope this was useful - thanks for being here 🩵

XO,

Aimara

>>> PS: I almost forgot to mention that I did write a blog post about fall & winter fabrics 😅 If you want to learn more, you can check it out here.​

More cozy articles that will help you stay warm and look good:

• ​How to find flattering sweaters for YOUR body type!​
• ​How to pack for winter travel in a carry-on (I created the full packing list for you!)
• ​6 easy early fall outfits with one striped sweater​